HP 4155B/4156B Semiconductor Parameter Analyzer Product Note-3 Prober Connection Guide. HP 4155B/4156B Semiconductor Parameter Analyzer

Transcription

1 HP 4155B/4156B Semiconduct Parameter Analyzer Product Note-3 Connection Guide HP 4155B/4156B Semiconduct Parameter Analyzer

2 - CONTENTS - 1. Introduction 2. General Infmation 2-1. Safety Precautions - - Interlock Circuit 2-2. Low Current Measurement - Guarding 2-3. Low Resistance Measurement - Kelvin Connections 2-4. Probe 3. Connecting to a 3-1. Installing the Connect Plate 3-2. Interlock Connections 3-3. GNDU Connections Safety Symbols The general definitions of safetysymbols used in this product note are listed below. WARNING The warning sign denotes a hazard. It calls attention to a procedure, practice, condition the like, which, if not crectly perfmed adhered to, could result in injury death to personnel. CAUTION The caution sign denotes a hazard. It calls attention to a procedure, practice, condition the like, which, if not crectly perfmed adhered to, could result in damage to destruction of part all of the product SMU Connections 3-5. VSU/VMU Connections 3-6. PGU Connections 3-7. Conclusion of Chapter 3 4. In Case Of Difficulty 4-1. SMU Oscillations due to Exceeding the Limits 4-2. Device Oscillations 4-3. Negative Resistance 4-4. Restrictions of Measurements Units 5. Appendix 5-1. Parts Infmation 2

3 1. Introduction This guide provides infmation on how to connect a prober to the HP 4155B/4156B Precision Semiconduct Parameter Analyzer. It also provides the necessary part numbers, and tips f making measurements. 2. General Infmation 2-1. Safety Precautions When you perfm measurements, always use a shielding box and an interlock circuit f safety Measurements should be perfmed in a shielding box in der: To prevent the operat from receiving an electric shock from the output voltage current of the HP 4155B/4156B. To minimize the effects of environmental noise and ambient light. Interlock circuit When you use a shielding box, you must install an interlock circuit. To prevent an operat from receiving an electric shock from high voltage (me than ± 40 V), connect the interlock (Intlk) terminal on the connect plate to a switch. The switch should turn on when the shielding box do is closed, and turn off when the shielding box access do is opened. (Refer to 3-2. Interlock Connections. ) 2-2. Low Current Measurement To reduce leakage current, you can use the guarding technique. Guarding Guarding reduces the leakage current between the measurement points and the instrument. This is imptant when you are measuring low current. Fig. 1 illustrates the they of guarding. The buffer amplifier (x1) keeps the potential of the GUARD conduct at the same potential as the FORCE conduct, so current does not flow between the FORCE and GUARD conducts. Therefe, the current measured by the SMU is the same as the current at the measurement point, because there is no leakage. F highly accurate measurements and minimal leakage, surround all FORCE lines from the SMU by a GUARD as far as possible. WARNING Do not touch the GUARD terminal with your bare hands, because of the danger of high voltage electrical shock. The potential of the GUARD terminal is equal to the output voltage. CAUTION Never connect the GUARD terminal to any other output, including CIRCUIT, FRAME GROUND, the GUARD terminal of any other unit. Doing so may damage the unit.. Use a grounded shielding box to minimize the effects of environmental noise and ambient light. To ground the shielding box, connect it to the chassis ground of the HP 4155B/4156B. Buffer GUARD FORCE Fig. 1 Guarding 3

4 2-3. Low Resistance Measurement To measure low resistance, connect the FORCE and SENSE terminals of the SMU to the using the shtest possible connection (F HRSMU and HPSMU only). When you measure a low resistance, high current flows through the. This high current increases the measurement err caused by the residual resistance of cables and contacts. To cancel the effect of this resistance, use Kelvin connections (4-wire) to extend the FORCE and SENSE lines separately to the. Kelvin connections Kelvin connections give good measurement results when you fce high current. Fig. 2 shows the equipment circuits f Kelvin and non-kelvin connections. of resistance R only. The impedance of the voltmeter is very high. Ideally, no current flows through rs1 and rs2, so the voltage drop across these resistances is negligible. Kelvin connections are effective even when fcing voltage. The voltage drop due to the residual resistance of the FORCE line wiring is fed back to the voltage source via a comparat in the SENSE line, thereby ensuring the specified voltage output at the sense point (where the FORCE and SENSE lines intersect). The input impedance of the comparat is high, so the current flow into the SENSE line is very low. Therefe, the output err is not significant if the SENSE line wiring has a residual resistance of 10 Ω less. With non-kelvin connections, the voltmeter measures the voltage drop of resistance rf1, R, and rf2. With Kelvin connections, the voltmeter measures the voltage drop rf1 rf1 rs1 rf2 R rs2 R rf2 (a) non-kelvin connection (b) Kelvin connection Fig. 2 Kelvin connection 4

5 2-4. Probe Usually, a prober will have probes consisting of a probe cable and needle. One side of the probe cable is connected to a probe needle. The other side is connected to the HP 4155B/4156B through the shielding box. HP recommends use of a full guarded needle, because nonguarded needles can cause leakage. Fig. 3 shows possible connections f a full guarded needle. The prober vend may let you select either triaxial coaxial connects. HP recommends using a triaxial connect to connect the SMU of the HP 4155B/4156B. To connect a triaxial connect to a coaxial connect of VSU/VMU/ PGU, use a triaxial - coaxial adapter ( ). (Refer to 5. Appendix.) If you have problems with these connections, you may want to solder them. HP provides two types of connect plates, a Connect Type and a Solder Type. Select the proper connection type f your prober. (Refer to 3-1. Installing the Connect Plate.) SMU Triaxial Cable VSU / VMU / PGU Coaxial Cable Direct FORCE (SENSE) GUARD If your probe doesn't have a probe cable, you may be able to use another recommended cable as a probe cable. (Refer to 5. Appendix.) When you use a probe card, these points are available. WARNING Be sure to use a shielding box and Intlk when you make a measurement. Do not use the adapters in Table 18 when the GUARD line connects to the outer conduct of the connect adapter. Because they connect GUARD line and outer conduct of the connect adapter, the potential of the GUARD terminal is equal to the output voltage and there is a potential f high voltage electrical shock at the adapter and connect. 3. Connecting to a This chapter provides infmation on connecting the prober. This infmation is f example only. If you need to know me about the connections between the connect plate and the prober, contact your prober vend. Probe Cable (triaxial) Probe WARNING Put inside a shielding box and use Intlk. The potential of this GUARD is equal to the output voltage. GUARD 3-1. Installing the Connect Plate Mount the HP 16495H/J connect plate on the side panel of your prober shielding box. One side of the plate is f connecting the cable from the HP 4155B/4156B. The other side of the plate is f connecting the cable to the prober. The HP 16495H/J have two options, Connect Type (opt. 001) and Solder Type (opt. 002). Use the Connect Type when the probe cable has a triaxial coaxial connect. Use the Solder Type when the probe cable has no connect, you have problems with the connection. Fig. 4 shows how to mount the connect plate. Table 1 and Fig. 5, Fig. 6, and Fig. 7 show me infmation about the connect plates. To install the connect plate, follow these steps. (1) Befe installing the connect plate, make sure that the HP 4155B/4156B and the HP 41501B are turned off. (2) Create the necessary openings and screw holes on your shielding box to match the connect plate. (3) Attach the connect plate with screws, nuts, and washers. (4) To prevent electric shock, make sure to install an interlock circuit. (Refer to 3-2. Interlock connections.) (5) Connect the cables between the HP 4155B/4156B and the connect plate. Use triaxial-coaxial adapter ( ) Recommended (full-guarded needle) FORCE Fig. 3 Probe Cable 5

6 The screws, nuts, and washers are not furnished. Each connect plate has four screw holes (3.2 mm in diameter). If you use a low noise probing system that has a built-in shield box, you may not need to install the connect plate and cables. This depends on the manufacturer. However, if the noise is not low enough, you will need to use a shielding box. If your prober has a connect assembly, you can connect cables to the connect plate of the shielding box through this connect assembly. When using this method, be aware of the limit of guard capacitance, and so on. (Refer to 4. In Case of Difficulty.) HP 4155B/4156B Option Opt. 301 Opt. 302 Opt. 311 Opt. 312 Table 1 Provided Connect Plates Stand-alone Product HP 16495H w / opt. 001 HP 16495H w / opt. 002 HP 16495J w / opt. 001 HP 16495J w / opt. 002 No. of Connects 6 x Triax / 6 x Coax / 1 x Intlk / 1 x GNDU 6 x Triax / 6 x Coax / 1 x Intlk / 1 x GNDU 8 x Triax / 4 x Coax / 1 x Intlk / 1 x GNDU 8 x Triax / 4 x Coax / 1 x Intlk / 1 x GNDU Connect Type (Front to Rear) Connect - Connect Connect - Solder Connect - Connect Connect - Solder Opening f Connect Plate Screw Washer Spring Washer Flat Screw Hole Nut Screw Connect Plate Screw Hole Nut Fig. 4 Mounting Connect Plate 6

7 GUARD FORCE (SENSE) Triaxial Connect (F SMU) Signal Line Coaxial Connect (F VS/VMU,PGU) SENSE Triaxial Connect (F GNDU) FORCE INTLK Terminal (a) Front View Triaxial Connect Ground Terminal Triaxial Connect Ground Terminal Common Terminal Common Terminal Coaxial Connect Coaxial Connect INTLK Terminal Triaxial Connect (F GNDU) INTLK Terminal Triaxial Connect (F GNDU) HP 16495H opt.001 HP 16495H opt.002 (The difference between the HP 16495H and J is the number of the Triax. and Coax. connects) (b) Rear View Fig. 5 Front View and Rear View of Connect Plate 7

8 Ø HP 16495H opt. 002 (Difference between the HP 16495H and J is the number of the Triax. and Coax. connects) Metal Cover Unit : mm Note : Metal cover is f preventing electrical shock. Metal cover is furnished with opt. 002 only. Fig. 6 Dimensions of the Connect Plate (HP 16495H/J) Triax. Coax. Triax. Coax. (a) Connect Type (opt. 001) (b) Solder Type (opt. 002) Fig. 7 Connection Type of Connect Plate ( Rear ) 8

9 3-2. Interlock Connections Fig. 8 (a) shows the interlock circuit needed f the shielding box, and Fig. 8 (b) and (c) show the pin assignments of the interlock connect on the connect plate. Interlock Cable Adapter If you already have an interlock circuit with a BNC coaxial connect, you can use an HP 16435A Interlock Cable Adapter. Switch and LED F dimensions of the switches and the LED, see Fig. 9, Fig. 10 and Fig. 11. F recommended parts, see table 2. First, install the switches to interlock the opening and closing of the do. F safety, use two switches in series. When me than ±40 V is fced from an SMU, the LED lights to indicate high voltage output. If the do of shielding box is open (the interlock terminals are open), the SMU cannot fce me than ±40 V. If the do is opened while the SMU output is me than ±40 V, the HP 4155B/4156B immediately drops the outputs of all units to 0 V. 12V HP 4155B/4156B 5V 10k Interlock Cable HP 16493J Opt m Opt.002 3m (a) Interlock circuit LED Interlock Switch Interlock open / close of the do Off : Do is open. On : Do is close. Conversely, if the do is closed (interlock terminals are shted), this function is disabled, and you can fce me than ±40 V. The connect plate and the HP 4155B/4156B have terminals f an interlock cable. To connect the interlock circuit, use an HP 16493J interlock cable. To prevent electric shock, make sure the interlock connection is as shown in Fig. 8. Interlock Switch LED (b) plug side view of Intlk terminal (c) wiring side view of Intlk terminal Fig. 8 Interlock Circuit Ø 6 WARNING Dangerous voltages of up to the maximum voltage of SMUs may be present at the FORCE, GUARD, and SENSE terminal when the interlock terminals are shted Cathode(-) Anode(+) 5 Ø 5 Ø 5.6 Units: mm Fig. 9 Dimensions of LED 9

10 Switch off Switch on 15.2 Max NC NC 2.8 Ø Units: mm Ø 3.1 COM Fig. 10 Dimensions of Interlock Switch ( ) Switch off Switch on Ø Units: mm Fig. 11 Dimensions of Interlock Switch ( ) Table 2 Parts Infmation Interlock Cable - 1.5m 1 - HP16493J 001 Interlock Cable - 3.0m 1 - HP16493J 002 Interlock Cable Adapter 1 - HP16435A - Switch Switch LED (VF ~= IF = 10mA)

11 3-3. GNDU Connections An SMU has FORCE (SENSE), GUARD, and, but a GNDU has SENSE, FORCE, and as shown in Fig. 12. A GNDU terminal has no GUARD line. When you connect it, pay attention to this connection. Triaxial Cable HP 16493H Opt m Opt m Apadter f GNDU Probe Cable (Triaxial) SENSE Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 FORCE Fig. 12 GNDU Terminal CAUTION Do not use the HP 16493C triaxial cable f an SMU to connect the GNDU to a. The GNDU can sink up to 1.6 A, and the maximum current rating f that cable is 1 A. Use an HP 16493H triaxial cable f a GNDU. When you connect to the prober, be sure to connect the FORCE line to the probe. Current flows only in the FORCE line, not the SENSE line. (Connect Type) Connect the triaxial connect using an adapter f GNDU ( ) as shown in Fig. 13. F this part, see Table 18 in 5. Appendix. F parts infmation, see Table 3. (Solder Type) Solder the SENSE line, and sht SENSE and FORCE as shown in Fig. 14. To connect the GNDU quickly f measurements where accuracy is not imptant, connect to the prober without shting SENSE and FORCE. F parts infmation, see Table 4. Fig. 13 Example of a GNDU non-kelvin Connection (Connect Plate Type: connect) Table 3 Parts Infmation Triaxial Cable -1.5m 1 - HP16493H 001 Triaxial Cable -3.0m 1 - HP16493H 002 Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Adapter f GNDU (triaxial (m) - triaxial (f)) Triaxial Cable HP 16493H Opt m Opt m Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 Insulat FORCE SENSE Probe Cable (Coaxial) FORCE Line SENSE Line Fig. 14 Example of a GNDU non-kelvin Connection (Connect Plate Type: solder) Table 4 Parts Infmation Triaxial Cable -1.5m 1 - HP16493H 001 Triaxial Cable -3.0m 1 - HP16493H 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

12 3-4. SMU Connections An SMU terminal is shown in Fig. 15. GUARD (1) Kelvin connections These instructions apply when all connections are Kelvin. Two probes must contact the wafer in this connection. Connect an HP 16493K Kelvin triaxial cable ( two HP 16493C triaxial cables) between the SMU and the connect plate. Connect the FORCE and SENSE lines to probes separately. (Only f HRSMU and HPSMU) (Connect Type) Connect the triaxial connect on the probe cable as shown in Fig. 16. To prevent oscillations, use sht cables. (Refer to 4. In Case of Difficulty.) F parts infmation, see Table 5. (Solder Type) Fig. 15 SMU Terminal FORCE (SENSE) Solder the FORCE line, SENSE line, and GUARD line as shown in Fig. 17. If the probe cable is triaxial, also solder the line. To prevent oscillations, use sht cables. (Refer to 4. In Case of Difficulty.) F parts infmation, see Table 6. Kelvin Triaxial Cable HP 16493K Opt m Opt.002 3m Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 Probe Cable (Triaxial) Probe Cable (Triaxial) Fig. 16 Example of an SMU Kelvin Connection (Connect Plate Type: connect) Table 5 Parts Infmation Kelvin Triaxial Cable -1.5m 1 - HP16493K 001 Kelvin Triaxial Cable -3.0m 1 - HP16493K 002 Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Kelvin Triaxial Cable HP 16493K Opt m Opt.002 3m Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 GUARD FORCE SENSE GUARD Insulat Probe Cable (Coaxial) Probe Cable (Coaxial) Fig. 17 Example of an SMU Kelvin Connection (Connect Plate Type: solder) Table 6 Parts Infmation GUARD Line FORCE,SENSE Line Kelvin Triaxial Cable -1.5m 1 - HP16493K 001 Kelvin Triaxial Cable -3.0m 1 - HP16493K 002 Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

13 (2) Kelvin to non-kelvin These instructions apply when the connections up to the Connect Plate are Kelvin, but the probe is a non-kelvin connection. Connect an HP 16493K Kelvin triaxial cable ( two HP 16493C triaxial cables) between the SMU and the Connect plate. (Only f HRSMU and HPSMU) Kelvin Triaxial Cable HP 16493K Opt m Opt.002 3m Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 Triaxial Cable m Probe Cable (Triaxial) Tee Triaxial BNC Unusable Note: Connect the cable and tee connect as shown. Due to space restrictions an adjacent connect is unusable. Since three connects are necessary f a Kelvin connection a connect plate must be used. Select the crect connect plate f your application. To make two Kelvin connections, use an HP 16495H. To make three Kelvin connections, use an HP 16495J. (Connect Type) Connect the triaxial connect on the probe cable as shown in Fig. 18. Connect the FORCE and SENSE lines on this side of the probe input terminal. A Tee Triaxial BNC adapter can be used. F parts infmation, see Table 7. Note: When connecting the cable and tee connect as shown in Fig 18, space restrictions make an adjacent connect unusable. Since three connects are necessary f a Kelvin connection a connect plate must be used. Select the crect connect plate f your application. To make two Kelvin connections, use an HP 16495H. To make three Kelvin connections, use an HP 16495J. (Solder Type) Connect the FORCE and SENSE lines on this side of the probe input terminal. Solder the FORCE line and the GUARD line, and sht FORCE and SENSE as shown in Fig. 19. If the probe cable is triaxial, also solder the line. F parts infmation, see Table 8. Fig. 18 Example of an SMU Kelvin - non-kelvin Connection (Connect Plate Type: connect) Table 7 Parts Infmation Kelvin Triaxial Cable -1.5m 1 - HP16493K 001 Kelvin Triaxial Cable -3.0m 1 - HP16493K 002 Triaxial Cable -0.4m Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Tee Triaxial BNC Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 SENSE GUARD Insulat GUARD Line Kelvin Triaxial Cable FORCE,SENSE Line HP 16493K GUARD Opt m FORCE Opt.002 3m Probe Cable (Coaxial) Fig. 19 Example of an SMU Kelvin - non-kelvin Connection (Connect Plate Type: solder) Table 8 Parts Infmation Kelvin Triaxial Cable -1.5m 1 - HP16493K 001 Kelvin Triaxial Cable -3.0m 1 - HP16493K 002 Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

14 (3) non-kelvin to non-kelvin These instructions apply when all connections are non-kelvin. Connect the HP 16493C triaxial cables between the SMU and the Connect plate. FORCE Triaxial Cable HP 16493C Opt m Opt.002 3m Probe Cable (Triaxial) (Connect Type) Connect the triaxial connect on the probe cable as shown in Fig. 20. F parts infmation, see Table 9. (Solder Type) Solder the FORCE line and the GUARD line as shown in Fig. 21. If the probe cable is triaxial, also solder the line. F parts infmation, see Table 10. SENSE Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 Fig. 20 Example of an SMU non-kelvin - non-kelvin Connection (Connect Plate Type: connect) Table 9 Parts Infmation Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Triaxial Cable HP 16493C Opt m Opt.002 3m Insulat GUARD FORCE Probe Cable (Coaxial) GUARD Line FORCE,SENSE Line FORCE SENSE Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 Fig. 21 Example of an SMU non-kelvin - non-kelvin Connection (Connect Plate Type: solder) Table 10 Parts Infmation Triaxial Cable -1.5m 1 - HP16493C 001 Triaxial Cable -3.0m 1 - HP16493C 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

15 3-5. VSU/VMU Connections A VSU/VMU terminal is shown in Fig. 22. Signal Line BNC Coaxia Cable HP 16493B Opt m Opt.002 3m Probe Cable (Coaxial) Fig. 22 VSU/VMU Terminal Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 Connect the HP 16493B coaxial cable between the VSU/VMU and the connect plate. (Connect Type) Connect the coaxial connect on the probe cable as shown in Fig. 23. If the probe cable is triaxial, use a triaxial - coaxial adapter ( ). F parts infmation, see Table 11. (Solder Type) Fig. 23 Example of a VSU/VMU Connection (Connect Plate Type: connect) Table 11 Parts Infmation Coaxial Cable -1.5m 1 - HP16493B 001 Coaxial Cable -3.0m 1 - HP16493B 002 Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Triaxial(f) - Coaxial(m) Adapter BNC Coaxia Cable HP 16493B Opt m Opt.002 3m Insulat Signal Line Probe Cable (Coaxial) Solder the signal line as shown in Fig. 24. F parts infmation, see Table 12. Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 Fig. 24 Example of a VSU/VMU Connection (Connect Plate Type: solder) Table 12 Parts Infmation Coaxial Cable -1.5m 1 - HP16493B 001 Coaxial Cable -3.0m 1 - HP16493B 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

16 3-6. PGU Connections A PGU terminal is shown in Fig. 25. BNC Coaxia Cable HP 16493B Opt m Opt.002 3m Probe Cable (Coaxial) Signal Line Fig. 25 PGU Terminal Connect the HP 16493B coaxial cable between the PGU and the Connect plate. Connect Plate HP16495H Opt. 001 HP16495J Opt. 001 Fig. 26 Example of a PGU Connection (Connect Plate Type: connect) Table 13 Parts Infmation (Connect Type) Connect the coaxial connect on the probe cable as shown in Fig. 26. If the probe cable is triaxial, use a triaxial - coaxial adapter ( ). F parts infmation, see Table 13. (Solder Type) Solder the Signal line and COM- MON as shown in Fig. 27. Coaxial Cable -1.5m 1 - HP16493B 001 Coaxial Cable -3.0m 1 - HP16493B 002 Connect Plate (Connect Type) 1 - HP16495H 001 Connect Plate (Connect Type) 1 - HP16495J 001 Triaxial(f) - Coaxial(m) Adapter BNC Coaxia Cable HP 16493B Opt m Opt.002 3m Insulat Signal Line Probe Cable (Coaxial) F parts infmation, see Table 14. Connect Plate HP16495H Opt. 002 HP16495J Opt. 002 Fig. 27 Example of a PGU Connection (Connect Plate Type: solder) Table 14 Parts Infmation Coaxial Cable -1.5m 1 - HP16493B 001 Coaxial Cable -3.0m 1 - HP16493B 002 Connect Plate (Solder Type) 1 - HP16495H 002 Connect Plate (Solder Type) 1 - HP16495J

17 3-7. Conclusion of Chapter 3 You can connect a prober to the HP 4155B/4156B using the previous instructions and examples. When making the connections, remember these points: (1) Befe making a measurement, confirm that the shielding box and interlock circuit are in place f safety and lowering noise effects. Mount connect plates in the shielding box as needed. (2) Use Kelvin connections when you measure low resistance (high current). (3) Use guarding (f example, a full guarded needle) when you measure low current. (4) Cables must be sht and stable f accurate measurement. The prober documentation may show different methods of connection. The connections described here are only examples. Fig. 28 shows the prober setup. Cables must be sht and stable f accurate measurement. To Measurement Unit Interlock Connect Plate Probe To Interlock Switches and LED Ground the shield box by connecting with the chassis of HP 4155B/4156B. (In Fig. 28, the shield box is connected to the ground through the connect plate.) Fig. 28 Example Cabling to 17

18 4. In Case Of Difficulty 4-1. SMU Oscillations due to Exceeding the Limits The HP 4155B/4156B have low current fcing and measurement capability through their SMUs. An SMU uses a feedback circuit to maintain very high stability of current / voltage sourcing. Therefe, the guard capacitance (a load f SMUs) of all connections to the SMU must be within certain limits to prevent SMU circuit oscillation. Select the proper cable type and length to keep guard capacitance low. F SMU limits, refer to 4-3. Restriction of Measurement Units Device Oscillations Ferrite Beads Test Device Fig. 29 Example of Ferrite 4-3. Negative Resistance If the has negative resistance characteristics as shown in Fig. 30 (b) and (d), the SMUs may oscillate, because SMUs operate as negative feedback amplifiers. To solve this problem: F a voltage-controlled negative resistance device: Connect G in parallel with the to cancel negative resistance as shown in Fig. 30 (a). To obtain an output I-V curve, use the following equation. Iy = I - G V F current-controlled negative resistance device: Connect R in series with the to cancel negative resistance as shown in Fig. 30 (c). To obtain an output I-V curve, use the following equation. Vz = V - R I If the resistance of the is less than 1 MΩ, you can use an R-Box. When measuring parameters of high-frequency devices, such as GaAs MESFETs high-frequency bipolar transists, oscillation may cause measurement problems. I V G Iy To solve this problem: F FETs, add resistive ferrite beads as close as possible to the gate. F bipolar transists, add resistive ferrite beads ( ) as close as possible to the base emitter, as shown in Fig. 29. I (a) F voltage-controlled negative Vz (b) Keep cables as sht as possible. Long cables cause oscillation because of their large inductance. (c) R (d) F current-controlled negative Fig. 30 Negative Resistance 18

19 4-4. Restrictions of Measurement Units The conditions in Table 15 are required f Measurement Units to measure accurately. (If the capacitance exceeds the limits, Measurements Units cannot measure accurately because of the SMU's oscillations.) Because high cable resistance causes an err in the feedback circuit of the SMUs, keep cables as sht as possible. This is especially imptant when making high current measurements. F me infmation on cables, see Table 16 and Table 17. Unit Maximum Capacitive Load Maximum GUARD Capacitance Maximum Shield Capacitance HRSMU 1000pF 900pF 5000pF Table 15 Restrictions of Measurement Units Cable Resistance Maximum allowable cable resistance when using Kelvin connections 10W (FORCE,SENSE) Typical Voltage Source Output Resistance FORCE line/ non-kelvin connection 0.2W MPSMU 1000pF 900pF 5000pF - Max. 0.3W Maximum allowable cable resistance when using Kelvin FORCE line/ non-kelvin connection HPSMU 1000pF 900pF 5000pF connections 0.2W FORCE: 0.7W (100mA to 1A) FORCE: 10W (<100mA) SENSE: 10W VSU 10uF GNDU <1uF - - FORCE: <1W - SENSE: <10W GUARD capacitance: Capacitance between FORCE (SENSE) and GUARD line Shield capacitance: Capacitance between GUARD and line 19

20 Table 16 Cable Reference Data PRODUCT OPT DESCRIPTION LENGTH CAPACITANCE RESISTANCE HP 16493B HP 16493C HP 16493H HP 16493K 001 BNC cable 1.5m 160pF 002 BNC cable 3.0m 330pF 001 SMU triaxial cable 1.5m 002 SMU triaxial cable 3.0m 001 GNDU triaxial cable 1.5m 002 GNDU triaxial cable 3.0m 001 Kelvin triaxial cable 1.5m 002 Kelvin triaxial cable 3.0m GUARD capacitance: 120pF Capacitance between GUARD and line: 900pF GUARD capacitance: 240pF Capacitance between GUARD and line: 1800pF Capacitance between FORCE and line: 550pF Capacitance between FORCE and SENSE line: 350pF Capacitance between FORCE and line: 1100pF Capacitance between FORCE and SENSE line: 700pF GUARD capacitance: 140pF GUARD capacitance: 260pF Resistance of FORCE line 220mW Resistance of FORCE line 400mW Resistance of FORCE line 160mW Resistance of FORCE line 320mW Resistance of FORCE line 80mW Resistance of FORCE line 150mW Resistance of FORCE line 170mW Resistance of FORCE line 340mW MAXIMUM CURRENT 1A 1A 1A 1A 1.6A 1.6A 1A 1A Table 17 Cable Reference Data PART-NUMBER DESCRIPTION CAPACITANCE RESISTANCE Coaxial cable 77pF/m Low-noise coaxial cable 130pF/m Coaxial cable 102pF/m Resistance of center conduct: 133mW/m maximum Resistance of center conduct: 114mW/m maximum Resistance of center conduct: 139mW/m maximum DIELECTRIC WITHSTAND VOLTAGE TEST JACKET EXTERNAL DIAMETER VOLTAGE RATING COLOR 500Vrms, 1minute 3.0mm Vrms, 1minute 2.7mm Vrms, 1minute 3.0mm AWG22 insulated wire (0.634mm in diameter) - 56mW/m V Black AWG24 insulated wire (0.511mm in diameter) - 89mW/m V Black AWG24 insulated wire (0.511mm in diameter) - 89mW/m V Brown AWG24 insulated wire (0.511mm in diameter) - 89mW/m V Red AWG24 insulated wire (0.511mm in diameter) - 89mW/m V Yellow 20

21 5. Appendix 5-1. Parts Infmation (1) Adapter Infmation If you need to make a connection between a triaxial connect and a coaxial connect, use a triaxial - coaxial adapter. Table 18 shows the adapter infmation provided by HP. If you need an adapter which is not provided, contact a local parts vend. WARNING Be sure to use a shielding box and Intlk when you make a measurement. Do not use the adapters in Table 18 when the GUARD line connects to the outer conduct of the connect adapter. Because they connect GUARD line and outer conduct of the connect adapter, the potential of the GUARD terminal is equal to the output voltage and there is a potential f high voltage electrical shock at the adapter and connect. Table 18 Adapter Infmation DESCRIPTION QTY PART-NUMBER ILLUSTRATION Triaxial(m) - Coaxial(f) Triaxial(f) - Coaxial(m) Triaxial(f) - Coaxial(f) Triaxial(m) - Coaxial(f) Triaxial(f) - Coaxial(m) Triaxial(f) - Coaxial(m) Triaxial(m) - Coaxial(f) Triaxial(m) - Triaxial(f) (f GNDU) Table 19 Cables Infmation Coaxial Cable f GNDU Low-noise Coaxial Cable f SMU and PGU (with select) Coaxial Cable f PGU AWG 22 Insulated Wire f GNDU (Black) AWG 24 Insulated Wire f VS/VMU (Black) AWG 24 Insulated Wire f VS/VMU (Red) AWG 24 Insulated Wire f VS/VMU (Yellow) AWG 24 Insulated Wire f VS/VMU (Brown) (2) Cable Infmation If your probe has no probe cable, you can use other recommended cables. Table 19 shows the recommended cables. If you use a PGU with an HP 16440A select, use a low-noise coaxial cable ( ). Table 20 Parts Infmation Screw Spring Washer Terminal Washer Nut (3) Other Parts If you need parts to fix a connect plate, see Table 20. Order the quantity you need. (The number of holes in a connect plate is four.) If you need ferrite beads f preventing oscillation, see Table 21. Table 21 Parts Infmation Ferrite Beads

22 F me infmation about Hewlett- Packard test and measurement products, applications, services, and f a current sales office listing, visit our web site: You can also contact one of the following centers and ask f a test and measurement sales representative. United States: Hewlett-Packard Company Test and Measurement Call Center P.O. Box 4026 Englewood, CO (tel) Canada: Hewlett-Packard Canada Ltd Spectrum Way Mississauga, Ontario L4W 5G1 (tel) (905) Europe: Hewlett-Packard Company European Marketing Centre P.O. Box AZ Amstelveen The Netherlands (tel) (31 20) Japan: Hewlett-Packard Japan Ltd. Measurement Assistance Center 9-1, Takakura-Cho, Hachioji-Shi, Tokyo 192, Japan (tel) (81) (fax) (81) Latin America: Hewlett-Packard Company Latin American Region Headquarters 5200 Blue Lagoon Drive 9th Flo Miami, Flida U.S.A. (tel) (305) /4220 (fax) (305) Australia/New Zealand: Hewlett-Packard Australia Ltd Joseph Street Blackburn, Victia 3130 Australia (tel) (Australia) (tel) (New Zealand) (fax) (61 3) Asia Pacific: Hewlett-Packard Asia Pacific Ltd 17-21/F Shell Tower, Times Square, 1 Matheson Street, Causeway Bay, Hong Kong (tel) (852) (fax) (852) Hewlett-Packard Company 1998 Data subject to change Printed in Japan 02/ E 22